21,239 research outputs found

    Monitoring the dispersion of ocean waste disposal plumes from ERTS-1 and Skylab

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    The author has identified the following significant results. About forty miles off the Delaware coast is located the disposal site for waste discharged from a plant processing titanium dioxide. The discharge is a greenish-brown; 15-20% acid liquid which consists primarily of iron chlorides and sulfates. The barge which transports this waste has a 1,000,000 gallon capacity and makes approximately three trips to the disposal site per week. ERTS-1 MSS digital tapes are being used to study the dispersion patterns and drift velocities of the iron-acid plume. Careful examination of ERTS-1 imagery disclosed a fishhook-shaped plume about 40 miles east of Cape Henlopen caused by a barge disposing acid wastes. The plume shows up more strongly in the green band than in the red band. Since some acids have a strong green component during dumping and turn slowly more brownish-reddish with age, the ratio of radiance signatures between the green and red bands may give an indication of how long before the satellite overpass the acid was dumped. Enlarged enhancements of the acid waste plumes, prepared from the ERTS-1 MSS digital tapes aided considerably in studies of the dispersion of the waste plume. Currently acid dumps are being coordinated with ERTS-1 overpasses

    Spectroscopic investigations of plasma properties quarterly summary report no. 2, 11 aug. - 10 nov. 1964

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    Performance of plasma source operated with helium - intensity and temperature profiles of source electronic instrumentation for detecting weak spectrum line

    Towards an Improved Test of the Standard Model's Most Precise Prediction

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    The electron and positron magnetic moments are the most precise prediction of the standard model of particle physics. The most accurate measurement of a property of an elementary particle has been made to test this result. A new experimental method is now being employed in an attempt to improve the measurement accuracy by an order of magnitude. Positrons from a "student source" now suffice for the experiment. Progress toward a new measurement is summarized

    Application of remote sensing technology to land evaluation, planning utilization of land resources, and assessment of westland habitat in eastern South Dakota, parts 1 and 2

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    The author has identified the following significant results. LANDSAT fulfilled the requirements for general soils and land use information. RB-57 imagery was required to provide the information and detail needed for mapping soils for land evaluation. Soils maps for land evaluation were provided on clear mylar at the scale of the county highway map to aid users in locating mapping units. Resulting mapped data were computer processed to provided a series of interpretive maps (land value, limitations to development, etc.) and area summaries for the users

    Mass transfer from a fluid flowing through a porous media

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    A mathematical model is developed for the process of mass transfer from a fluid flowing through a packed column. Mass loss, whether by absorption or adsorption, may be significant. This is appropriate for example when removing contaminants from flue gases. With small mass loss the model reduces to a simpler form which is appropriate to describe the removal of contaminants/pollutants from liquids. A case study is carried out for the removal of CO2 from a gas mixture passing over activated carbon. Using the experimental parameter values it is shown, via non-dimensionalisation, that certain terms may be neglected from the governing equations, resulting in a form which may be solved analytically using a travelling wave substitution. From this all important quantities throughout the column may be described; concentration of gaseous materials, amount of material available for mass transfer, fluid velocity and pressure. Results are verified by comparison with experimental data for the breakthrough curve (the amount of carbon measured at the column outlet). The advantage of the analytical expression over a purely numerical solution is that it can easily be used to optimise the process. In the final section we demonstrate how the model may be further reduced when small amounts of contaminant are removed. The model is shown to exhibit better agreement than established models when compared to experimental data for the removal of amoxicillin and congo red dye from water

    Clustering on very small scales from a large sample of confirmed quasar pairs: Does quasar clustering track from Mpc to kpc scales?

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    We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes of g<20.85g<20.85 and proper transverse separations of 25h1\sim 25\,h^{-1}\,kpc. Our sample of binary quasars, which is about 6 times larger than any previous spectroscopically confirmed sample on these scales, is targeted using a Kernel Density Estimation technique (KDE) applied to Sloan Digital Sky Survey (SDSS) imaging over most of the SDSS area. Our sample is "complete" in that all of the KDE target pairs with 17.0R36.2h117.0 \lesssim R \lesssim 36.2\,h^{-1}\,kpc in our area of interest have been spectroscopically confirmed from a combination of previous surveys and our own long-slit observational campaign. We catalogue 230 candidate quasar pairs with angular separations of <8\arcsec, from which our binary quasars were identified. We determine the projected correlation function of quasars (Wˉp\bar W_{\rm p}) in four bins of proper transverse scale over the range 17.0R36.2h117.0 \lesssim R \lesssim 36.2\,h^{-1}\,kpc. The implied small-scale quasar clustering amplitude from the projected correlation function, integrated across our entire redshift range, is A=24.1±3.6A=24.1\pm3.6 at 26.6 h1\sim 26.6 ~h^{-1}\,kpc. Our sample is the first spectroscopically confirmed sample of quasar pairs that is sufficiently large to study how quasar clustering evolves with redshift at 25 h1\sim 25 ~h^{-1} kpc. We find that empirical descriptions of how quasar clustering evolves with redshift at 25 h1\sim 25 ~h^{-1} Mpc also adequately describe the evolution of quasar clustering at 25 h1\sim 25 ~h^{-1} kpc.Comment: 16 pages, 8 figures, 6 tables, Accepted for publication in MNRA

    Dictionary Matching with One Gap

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    The dictionary matching with gaps problem is to preprocess a dictionary DD of dd gapped patterns P1,,PdP_1,\ldots,P_d over alphabet Σ\Sigma, where each gapped pattern PiP_i is a sequence of subpatterns separated by bounded sequences of don't cares. Then, given a query text TT of length nn over alphabet Σ\Sigma, the goal is to output all locations in TT in which a pattern PiDP_i\in D, 1id1\leq i\leq d, ends. There is a renewed current interest in the gapped matching problem stemming from cyber security. In this paper we solve the problem where all patterns in the dictionary have one gap with at least α\alpha and at most β\beta don't cares, where α\alpha and β\beta are given parameters. Specifically, we show that the dictionary matching with a single gap problem can be solved in either O(dlogd+D)O(d\log d + |D|) time and O(dlogεd+D)O(d\log^{\varepsilon} d + |D|) space, and query time O(n(βα)loglogdlog2min{d,logD}+occ)O(n(\beta -\alpha )\log\log d \log ^2 \min \{ d, \log |D| \} + occ), where occocc is the number of patterns found, or preprocessing time and space: O(d2+D)O(d^2 + |D|), and query time O(n(βα)+occ)O(n(\beta -\alpha ) + occ), where occocc is the number of patterns found. As far as we know, this is the best solution for this setting of the problem, where many overlaps may exist in the dictionary.Comment: A preliminary version was published at CPM 201
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